The present invention relates to a water-proof connector in which water proofing is achieved by press fitting in the inner periphery of a connector housing a rubber plug through which wires are put after the terminals of the wires have been connected to the connector housing, and more particularly to the locking structure of terminals to be connected to the water-proof connector.
One of such conventional locking structures of terminals to be connected to water-proof connectors is a double-locking structure which comprises a primary locking mechanism in which the lances of terminals when inserted are locked at a locking portion provided in terminal receiving cavities and a secondary locking mechanism in which a separate retainer is fitted in either from the front or rear side of the inserted terminals so as to prevent the terminals from coming off.
However, in a locking structure having such a secondary locking mechanism in which a retainer is fitted in from the rear side of the terminals to press against the rubber plug behind the terminals, if the terminals are inserted improperly they may not be pushed forward sufficiently to be located at a normal position, and imperfect insertion is thus likely to take place wherein the action of the primary locking mechanism cannot be expected to function. In contrast, in the case of a secondary locking mechanism in which the retainer is fitted in from the front side of the terminals, the retainer is easily fitted in, even if the terminals are inserted improperly, and this often makes it impossible to detect an error of imperfect insertion of the terminals. Thus, the action of the double-locking structure for the terminals often cannot be expected to function in either of the above cases.